The present invention provides a novel thermoelectric semiconductor material having excellent thermoelectric property which is not lowered like a conventional PbTe-based or PbSnTe-based semiconductor material even if a strength is improved by sintering. The thermoelectric semiconductor material of the invention is characterized by having chemical formula AB2X4 (where, A is a simple substance or mixture of Pb, Sn and Ge (IV family elements), B is a simple substance or mixture of Bi and Sb (V family elements), and X is a simple substance or mixture of Te and Se (VI family elements). In this case, a spark plasma sintering device is used to apply a pulsed current through the powder material to cause an electrical discharge among particles of the powder to synthesize the compound AB2X4 having a uniform structure. And, the invention synthesizes a compound, which is to be a thermoelectric semiconductor material, so to have a uniform structure. Using a spark plasma sintering device, a pulsed current is applied to the powder material to cause an electrical discharge among particles of the powder to synthesize compound PbBi2Te4 having a uniform structure.